Additional replacement patterns

[mheap]

Suggested by @mathiasbynens in #12:

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Other possible replacements (you'd probably want to do these globally, in all files):

• https://github.com/<org>/<repo>/tree/<old> (example)
• https://github.com/<org>/<repo>/blob/<old> (example)
• https://raw.githubusercontent.com/<org>/<repo>/<old> (example)